Portable incinerator



' Dec. 8, 1964 R. M. SHERMAN 3,160,122

PORTABLE INCINERATOR Filed Sept. 26, 1963 4 S e -Sh et 1 INVENTOR. RALLSTON M. SHERMAN 5. 3% W V M ATTORNEYS Dec. 8, 1964 R. M. SHERMAN PORTABLE INCINERATOR 4 Sheets-Sheet 2 Filed Sept. 26, 1963 ATTORNEYS Dec. 8, 1964 R. M. SHERMAN PORTABLE INCINERATOR 4 Sheets-Sheet 4 Filed Sept. 26, 1963 5o f/r C) C) C) Q 33 III U I) U) 0) 0%) O (I) C RALLSTON MI. SHERMAN BY FIG.9

ATTORNEYS United. States Patent C) 3,169,122 PGRTABLE HNCENERATOR Rallston M. Sherman, Glastonbury, Conn assignor to The Silent Glow Gil Eurner Corporation, Hartford, Conn, a corporation oi Connecticut Filed Sept. 26, 1963, Ser. No. 311,885 4 Qlaims. (Q1. lllll8) The present application is a continuation-in-part of my application Serial No. 184,064.

My present invent-ion concerns apparatus for burning trash, rubbish and other combustible material for disposing of the same. More particularly it aims to provide a relatively compact and light-weight yet ruggedv structure inexpensively manufacturable of sheet metal and adapted to be knocked down for packaging and shipment.

Among other objects and advantages are the provision of a readily portable incinerator constructed and operativelyarranged to consume under an hydroxylative burning action the material charged thereto, with a minimum production of smoke or objectionable odors.

in various respects the present invention affords an improved means and apparatus utilizing operative principles as disclosed in my Patent 2,952,226 of September 23, 1960.

The above and other objects of the invention will be best understood from the following description when read in the light of the accompanying drawings of a specific embodiment of the invention selected for illustrative purposes, While the scope of the invention will be more particularly pointed out in the appended claims.

In the drawings:

FIG. 1 is a side elevation of an incinerator according to the invention;

FIG. 2 is a top plan view of such incinerator;

FIG. 3 is a bottom plan view of the same;

FIG. 4 isa central vertical section as on the line 44 of FIG. 1 and upon a larger scale;

FIG. 5 is a horizontal sectional view located as on the line 55 of FIG. 4;

FIG. 6 is a horizontal section located as on the line 66 of FIG. 4;

FIGS. 7 to 9 show modifications, wherein FIG. 7 is a view corresponding to the central portion of FIG. 5, with the head chamber and stack ring omitted for clarity;

FIG. 8 is an enlarged vertical sectional fragmentary view as on the line 8 of F IG. 7; and

FIG. 9 is a substantially central vertical sectional view, similar to an upper portion of FIG. 4-, on a larger scale.

As illustrated in the drawings the incinerator comprises a vertical tubular structure comprising an erect main casing ll. While this may be variously shaped including the cylindrical, for convenient fabrication and packaging it is flat-sided, being shown as quadrilateral and of general truncate pyramidal form somewhat smaller at the top than at the base. The slightly inclined generally vertical side walls 2, 3, 4 and 5 comprise similar sheet metal members as for example of aluminized mild steel of 20 gauge or thereabouts. These are adapted to be erected into the four-sided chamber-defining structure illustrated, as by disposing the vertical side edges of the respective side walls 2 to i in angular abutting relation presenting four upright corner portions. These main wall members are fastened in the erected position, each having for this purpose along one vertical side edge a flange adapted to overlap the non-flanged edge of the adjoined wall and to be secured together preferably detachably as by screw bolts.

This main chamber-forming casing 1 is open at the bottom and is provided with supporting legs shown as angle bars 7 detachably secured as by rivets or screw bolts 8 at the respective lower corners of the casing and extend- Patented Dec. 8, i964 ice ing below the bottom thereof so as to support it in vertically spaced relation above the horizontal surface upon which the incinerator is to be placed for use.

The lower and wider approximately half-portion of the casing l is adapted to stand over and enclose a rectangular box-like lower charge-receiving and combustion chamber element designated generally at it) likewise constructed of sheet metal, including an imperforate horizontal bottom wall 11 carried at the lower horizontal edges of opposed pairs of vertical walls 12, and being open at the top. The horizontal upper margins of said inner lower chamber vertical walls 12 are integrally or otherwise formed with laterally outturned flanges 13 along the major portions of the respective walls but terminating short of the ends thereof so as to provide corner openings as seen at 14, 14, etc, FIGS. 3, 4 and 6.

While in some instances the flanges 13 of the lower chamber it and the adjacent wall portions of the casing 1. may be provided with means for interconnecting them, with the chamber 10 suspended by the casing if desired with its closed bottom out of contact with the incinerator supporting surface, it is found preferable that this chargereceiving and ash-collecting chamber 30 stand independently on the supporting surface where it is encompassed andheld by and relative to the main casing 1 set down enclosingly about it. The edges of the inner chamber flanges 13 are shaped and proportioned for snugly fitting against the inner faces of the casing walls, leaving said vertical air-flow directing and controlling passages 14, 14, etc. at least at the four open corner areas previously mentioned. Above the lower portion 10 of the confined space within the casing l is the upper combustion chamber portion 15 also-within said casing.

In keeping with the principles as disclosed in my said Patent 2,952,226 the incinerator of the present invention is constructed and arranged to take advantage of hydroxylative combustion as distinguished from ordinary carbonic combustion. The incinerator accordingly is so devised that among other things it will predominantly burn the charge in a manner to distill from it combustible gases having dominant quantities of hydro-carbon molecules andwhereby such largely hydro-carbon gases produced under a relatively low temperature and slow burning are attended with a purplish flame as characteristic of hydroxylative combustion.

Such action is obtained with the incinerator of the present invention by so heating the charge as to distill a large volume of combustible gases from it and by causing those gases to burn as they flow away from the charge through a combustion zone in which the hydrocarbon molecules of the gases progressively absorb oxygen as they so flow.

Such absorption of oxygen results in the progressive formation, along the path of flow, of hydroxyl (OH) groups, the intermediate products of the absorption being alcohols and aldehydes. These alcohols and aldehydes then under the influence of heat and temperature burn to carbon monoxide and hydrogen, and finally to carbon dioxide and water vapor. The purplish flame results from the formation of the aldehydes and then the burning of them. This purplish flame combustion takes place at a much lower temperature and more slowly than would be the case were the gases burned by so-called carbonic combustion, which latter would heat the combustible gases to such high temperature as would crack the hydrocarbon molecules to liberate smoke-forming carbon particles therefrom, all of which particles would not be consumed by the burning, the yellow flame which characterizes carbonic combustion resulting from the heating of such carbon particles to incandesecence.

Accordingly the incinerator of the invention includes above the lower portion 1i and the overlying upper por- Zia tion 15 of the confined space within the casing 1 a further chamber-defining top element or head section designated generally at 20, presenting further confined space and other combustion chamber volume for the incinerator as a whole. Such head element 219 as illustrated isadapted to be removably superimposed at and upon the upper rim of the described casing -1.

Such head 20 comprises a main supporting plate 21 shaped and dimensioned for supportive reception upon the upper edges of the walls 2 to 5 of said casing 1. This herein substantially rectangular plate 21 has continuously about its periphery a downturned positioning flange 21x, FIGS. 1, 4 and 5. Centrally it is formed with a large and herein circular aperture 22, FIGS. 4 and 5, encompassed by anupstanding flange 22a for receiving about it the lower portion of a secondary combustion chamber element 30 shown of vertical cylindrical shape conformant to and having snug fitting reception at said central aperture 22 and around said flange 22a thereof. v

Depending from the under face of the plate 21 and Within the surrounding upper portion of the walls of the casing 1 is a lower horizontal plate 24 having an upturned generally vertical flange 25 about the outer side edges thereof and spacing this lower plate 24 vertically from and relative to the upper and outer or cover plate 21. These two plates are rigidly secured together as by spacer bolts 26 shown at the several corner portions, FIGS. 4 and 5; see also modificational FIGS. 7 and 9. Between them they define in effect a carbureting space in which jets or streams of supplemental air may be flowed laterally into commingling contact with streams of burning gases flowing vertically from the first combustion chamber 1.

Said lower plate 24 also has a central and herein circular aperture 27, of substantially lesser diameter than aperture 22 of the cover plate 21, and also having a surrounding vertical flow-directing flange 27a. The horizontal portion of this plate 24 also desirably has a series of smaller flow-controlling apertures 28. FIGS. 4 and 5, and seen also in FIGS. 7 and 9, arranged about the main central aperture 27. The central vertically open space between the plates 21 and 24 provides for flow of distilled gases from the primary combustion chamber to the confined combustion space within the head chamber 30 for the burning therein of jet-flowing ignited streams of gases produced in and flowing upwardly therefrom, and into which the mentioned additional streams of combustion air are admitted and admixed. It is noted that not only the central aperture 27 but also each of the perforations 28 around it are adapted for discharging in jet-like streams the combustible gaseous products generated in the confined space of casing 1.

The secondary combustion chamber 39 of the head 26) comprises a cylindrical drum-like element fashioned of similar but foramin-ous sheet metal. Said element is open at the bottom and has in the cylindrical vertical wall a multitude of perforations 31 in closely spaced array and distributed over the entirety of said wall. These provide for lateral outward flow of the burning gases from the space within said chamber 30, subject in some instances to recirculation of a portion of such gases. This perforatewalled upper chamber element 30 is supported on and by the main base plate 21 of the head 2%, the lower end of said chamber 30 being shaped and dimensioned to fit snugly about the mentioned upright flange 22a of said plate 21, on which latter the chamber 30 rests, preferably removably. I

At the upper end the chamber 30 is closed as by a top plate 32 having an upturned rim 33 snugly fitted in and secured as by welding to the top margin of the perforate cylindrical wall of the drum 30. Said top plate 32 may have a small central aperture 34 through which a lighted match may be dropped or a taper inserted for ignition of the load charged into the main chamber 19.

The head structure 20 further comprises an outer cylindrical stack ring or flue-like element 40 surroundingand laterally spaced from the chamber element 30. It and the other main elements of the head section 20 may be of sheet metal similar to that of the casing 1. It comprises a vertically disposed annular wall of a height to extend in this instance from at or somewhat above the supporting plate 21 upwardly to a level at or adjacent the top of the chamber 30, being shown as terminating slightly below the latter. 7 It is supported on said main plate 21, in vertically spaced relation thereto in the example of FIGS. 1 to 6, as by a series of leg brackets 41, four of which are seen inFIG. 5 spaced apart; see also FIGS. 1 and 2. The upperends of such spacer and supporting legs 41 are welded or otherwise secured to the lower edge of theflue ring 40, the lower ends being angularly turned and welded or otherwise fixed as at 42 upon the upper face of the adjacent marginal portion of the plate 21. For additional rigidity this chamber-surrounding and passage-forming ring or fiue element 40 may be formed with one or more circumferentially extending corrugate ribs 43.

In the operation of the incinerator the entire head section 2% is lifted off from the casing 1, opposed hand grips 46 being provided for, the purpose on the outer wall of the outer ring element 40; FIGS. 1, 2 and 4. The waste material to be disposed of is charged through the thus open top of the casing 1 into the interior, up to substantially the full capacity of its volume if desired, including not only the lower combustion chamber portion 10 but also the confined space 15 above it in the casing 1, but leaving suflicient open volume for replacement of the head section 26. In such charging the material for combustion is formed and erected into a body having lower outer surfaces in the lower combustion chamber portion 10 and having upper outside surfaces within and toward the top of the main chamber portion 15 of the casing 1. Ignition may be accomplished as by twisting a piece of paper into a torch, lighting and dropping it into the upper portion of the casing 1 and thereupon replacing the head section 20. Or if preferred the covering upper section 20 may first be replaced and the ignition then accomplished as by dropping a lighted match through the top center aperture 34 of the head section.

Combustion of the ignited charge is initially maintained by air admitted at the bottom of and upwardly through the flow-restricting and controlling corner passages 14, 14, etc. of the casing. The amount of air so admitted is generally insufficient to support complete combustion of the charge yet is sufiicient to generate enough heat to distill from it combustible hydro-carbon gases. Ignited streams of these gases pass upwardly from the chamber of easing 1 through the main central aperture 27 and also the surrounding aperture series 28 of the lower head plate 24 and on up via the opening 22 of the upper head plate 21 and so into the perforate-walled head chamber 30. Thus said burning gas streams flow in the form of divided and ignited streams or jets of the combustion gases. Suplemental combustion air is admitted in the form of jets to the upper space in the chamber of casing 1 and especially such space between the upper and lower head plates 21, 24 as at the holes 29 within the vertical prolongation of the stack ring 40, and likewise at other holes 29x in plate 21 outside said stack ring prolongation where such are employed. As by means of such series of holes 29, 29x the additional combustion air enters as around the base of the outer ring 40, and contacts at substantially right angles the vertically flowing ignited gas streams, such additional infiowing combustion air being available to the space at the upper portion of the casing chamber 1 including that between the lower and the upper head plates 24, 21.

Thus While the ignited distilled gases are flowing in such space of theincinerator they are contacted transversely of the upward flow direction and progressively along said direction of flow by the described combustion air jets. This is accomplished in a manner whereby the burning gases are intimately mixed extensively and progressively with the additionally admitted air whereby the hydroxylative combustion of the gases is continued following the starting thereof at a relatively slow rate within the chamber volumes of the casing 1 as above described. This is accomplished with a substantially complete absence of discharge of smoke from the flue ring element 4%}, smokeforming carbonic combustion of the charge being reduced to a minimum. In general any smoke-forming particles from such small extent of carbonic combustion as may occur in the casing 1 are consumed in the course of the hydroxylative combustion of the gases in the lower portion of the superposed head chamber 30 and in their lateral escape therefrom via the multitudinous apertures 31, 31 of said chamber 30 and into the annular passage of said outer flue element 44?.

Consequently in operation the incinerator is substantially free of smoke and objectionable odor, to such extent that the device may be utilized as a space heater for terraces and like outdoor areas, while in addition the fiat horizontal top Wall of the upper chamber 30 is available as a hot plate or grill for outdoor cooking purposes.

Similarly as in my Patent 2,952,266 when combustion of the waste material content has so reduced the latter that not enough hot gases are discharged into the upper chamber 313 to maintain a draft therethrough, there may occur an automatic reversal of the draft with the casing 1 itself acting as a stack, air being supplied as through the upright corner passages 14, 14, etc. of the lower combustion chamber portion 10, with the gaseous combustion products discharging to the stack as at the apertures 29.

With the disclosed construction it is observed that all combustion air for the incinerator is admitted along or through perforations in or adjacent the lateral walls of the casing and chamber forming elements, as for example along the corner passages 14, 14 and through the hole series 29, 29x, and tends to cool the walls and to keep the flame out of contact with them. This relatively low temperature operation promotes the durability of the incinerator and permits its fabrication of relatively inexpensive mild sheet steel.

incinerators as illustrated and described may be constructed in different sizes. Highly satisfactory results have been obtained with apparatus as disclosed wherein the overall height of the main casing 1 including the supporting legs is 27 in., the casing walls being approximately 19 in. in width at the lower end and 12% in. at the upper end. The head section 2% in such example has an overall height of 5 /2 in. above the carrier plate 21 at the top of the casing 1, with an outer diameter for the upper chamber member 3% of 9 /2 in., with the multitudinous wall apertures of approximately /a in. diameter. The flow passages such as the gas discharge apertures 28 in the head plate 24 are suitably in such instance it; in. diameter. It will be understood that these dimensions are noted merely by way of example and without limitation thereto.

In the modified structure illustrated in FIGS. 7 to 9 the overall construction and arrangement of the incinerator is similar to that shown in F168. 1 to 6. Corresponding parts accordingly are designated by the same reference numerals and may be similar as in the earlier views unless otherwise stated. Noting particularly the enlarged vertical sectional view FIG. 9 the outer flue element or stack ring 49' of the head section 29 is again rigidly secured to the upper head plate 21 as by welding, with or without the provision of angular brackets such as 41 of FIGS. 1 to 6. Said upper plate 21 of the head desirably also is formed with flow apertures distributed around the base of the inner perforate chamber element 3%, and including an inner series 29 disposed in said upper horizontal plate 21 at the lower end of the annular space between the perforate chamber 39 and the flue 40', and an outer aperture series 29x also in the plate 21 but outside said fiue element 49 and spaced circumferentially about it. Each of these apertures may be of a size comparable to that of the perforations 31 of the drum-like head chamber 36 as for example approximately /2 in. in diameter.

In this instance the flue element 40' is formed near or somewhat below mid-height thereof with a restriction extending fully circumferentially about and within the annular space between said flue 4i! and the perforate wall of chamber 30. Such passage restriction promotes a reduced or negative pressure below it with attendant retarding efiect as to up flow above it and in some instances, depending on the extent of restriction, effecting a down flow tendency as to some of the burning gases issuing from the lower portion of chamber 30 that is below such restriction, assisting the commingling of the secondary air and the hydroxylative burning of the gases. Such restriction as illustrated in FIG. 9 may be in the form of an inwardly directed corrugation 43x.

In the embodiments of FIGS. 7 to 9 as in the earlier example the relatively slow and low temperature burning of the trash load and the attendant hydroxylative combustion of the resulting distilled gases is aided by the plurality of in-fiowing jets of supplemental air which enter at the exterior apertures 29x of plate 21, at the various points distributed completely around the head section 26, with air streams or jets being directed horizontally inwardly and at right angles to the upward direction of the flow of flaming gas streams and so as to become commingled intimately therewith Within the horizontal space s, see FIG. 9, between the lower and upper plates 24 and 21 of the head section 20. At the same time the inner series of apertures 29 of plate 21 disposed at the base of the annular space between the flue 40' and the chamber 30 and aided by the restriction 43x and the resultant pressure reduction and up-fiow-retarding action below it promote the hydroxylative burning of the streams of ignited combustion gases by reason of the increased or prolonged jetflow of the supplemental air thus provided for coaction with said gases. The gases are thus fully or nearly fully consumed before the discharge of any remnant thereof occurs at the open upper end of the stack space 0; again see FIG. 9.

As a further feature adapted to afford even more accurate control as to rate of burning and for adjustment of the incinerating action to particular atmospheric or other ambient conditions, the external supplemental air admitting apertures 29x may be provided with adjustable damper means such as illustrated for example in FIGS. 7 and 8.

As there shown such means is in the form of a flat ring 50 of an external size and shape to be received upon the top surface of the top plate 21 of the head section 20 and having a circular inner edge concentric with the vertical axis of the incinerator as a whole and spaced laterally outwardly from the circumferential margin of thewall of the stack ring or flue element 40', so as to lie outside the supporting foot brackets 41 thereof. Such damper ring is held flatwise in position on the head plate 21, with capacity to be rotatively shifted relative thereto, as by means of holder fingers 51, 51 shown in FIG. 7 at each of the four corners of the incinerator casing 1 and having raised inturned lips overlapping the outer margin of said damper ring. The latter may conveniently be formed with a handle 52 for manipulating it. This damper ring 59 is formed with a series of vertical apertures 53 matching the apertures 29x of the plate 21 so that in an open position of the damper 50 as determined by horizontal turning movement thereof by the hand lever 52 the damper holes 53 and the plate holes 29x may be fully aligned, or may be wholly or partially closed for controlling the volume of the supplemental air jets to be commingled with the outfiowing streams of burning gasses.

My invention is not limited to the particular embodiments thereof illustrated and described herein, and I set forth its scope in my following claims.

I claim:

1. A portable knockdown incinerator comprising sheet metal wall means defining an erect casing having vertically upwardly and inwardly inclined side walls and being open at the top and bottom with feet depending from the side walls for supporting the casing in spaced relation above a positioning horizontal surface,

said casing having disposed within the lower portion a receiver for a charge of material to be burned and including a floor-defining bottom wall and vertical side walls laterally spaced from the casing at their lower portions, said receiver together with the interior of the casing above it defining a primary combustion chamber,

the side walls of said receiver approaching the casing side walls at a mid-height region thereof and there having lateral outward flanges horizontally spacing it from the casing side walls to form vertical air flow passages upwardly along them to said combustion chamber,

and a carburetting burner head at the top of the casing and there defining a second combustion chamber, said burner head comprising a cover-like supporting plate fitting and removably seating on the casing top and having a large central aperture,

an upstanding perforate wall surrounding and vertically open to said aperture and having a horizontal top wall defining with said perforate wall a topclosed second combustion chamber,

a horizontal bottom plate of similar circumferential extent as and spaced below said supporting plate and having a vertical marginal wall connecting it to said supporting plate to form therewith an intermediary chamber between the primary combustion chamber of the casing and said second combustion chamber,

said bottom plate having a main central aperture concentric with but of smaller diameter than the central aperture of said supporting plate and also having a series of relatively small apertures distributed about said main central aperture and said supporting plate also having a circumfere'ntially distributed aperture series radially outward of said bottom plate apertures,

said burner head further comprising a vertical stack ring surrounding and annularly spaced from said upstanding perforate wall of the head and carried on and above said supporting plate,

said stack ring, said perforate-walled second combustion chamber and said intermediary chamber and all said apertures thereof together being constructed and arranged to provide passages for jet flow of external supplemental air laterally and inwardly via said intermediary chamber to said second combustion chamber so as to contact transversely and progressively along the flow direction ignited streams of combustion gases flowing up from the primary combustion chamber of the casing and thereby continuing in said second chamber by hydroxylative combustion the burning of such gases.

2. A portable knockdown incinerator according to claim 1 wherein said small apertures of the supporting plate of the burner head include some external to and others internal to the annular space between die stack ring and the perforate chamber wall of said head.

, t 3 3. A portable knockdown incinerator according to claim 2 wherein said burner head supporting plate is provided with adjustable damper means for controlling the inflow of air at said externalapertures of the supporting plate to any desired extent up to total closure thereof.

4. A portable knockdown incinerator comprising sheet metal Wall means defining an erect casing having vertically upwardly and inwardly inclined side Walls and being open at the top and bottom with feet depending from the side walls for supporting the casing in spaced relation above a positioning surface,

an open-top box fiorm charge-receiver within the lower portion of said casing and defining with the upper casing portion a primary combustion chamber, said receiver including a bottom wall near the base of the casing and vertical side walls laterally spaced from the casing at their lower portions and approach ing and having locating contact with the casing side walls at mid-height thereof, the upper margins of the receiver side walls having cirtcunrferentially interrupted lateral projections for positioning Contact with the casing side walls while providing thereat passages for upward flow of air from the casing base to said primary combustion chamber,

and a carburettmg burner head at the top of said casing and compnising a horizontal carrier plate fitted upon the upper edges of the casing side walls and having a large central aperture receiving thereat a second combustion chamber having above the carrier plate a vertical circumferential wall and a substantially closed top wall and having a bottom wall below the carrier plate,

said bottom wall of said second combustion chamber having a main central aperture concentric with that of the head carrier plate and a series of smaller apertures distributed circumferentially about said central aperture and together with the latter providing for upward jet flow of ignited streams of combustion gases distilled from burning material in the primary combustion chamber of the casing,

said carrier plate also having a series of apertures distributed circumferentially about it at locations radially outward of said apertures of the second combustion chamber bottom wall and providing for inward jet flow of additional compustion air into contact with the said ignited streams of gases transversely of the latter and progressively along the flow direction thereof for continuing in said second combustion chamber the burning of said gases by hydroxylative combustion,

said burner head further comprising a stack ring above the carrier plate and surrounding and laterally spaced from the vertical wall of the second combustion chamber to define an annular space around it,

and said vertical Wall of the second combustion chamber having a multitude of perforations distributed both circumferentially and vertically thereof for escape of gaseous combustion products from said second combustion chamber into and through said annular space between it and said stack ring.

No references cited.

JAMES W. WESTHAVER, Primary Examiner. 

1. A PORTABLE KNOCKDOWN INCINERATOR COMPRISING SHEET METAL WALL MEANS DEFINING AN ERECT CASING HAVING VERTICALLY UPWARDLY AND INWARDLY INCLINED SIDE WALLS AND BEING OPEN AT THE TOP AND BOTTOM WITH FEET DEPENDING FROM THE SIDE WALLS FOR SUPPORTING THE CASING IN SPACED RELATION ABOVE A POSITIONING HORIZONTAL SURFACE, SAID CASING HAVING DISPOSED WITHIN THE LOWER PORTION A RECEIVER FOR A CHARGE OF MATERIAL TO BE BURNED AND INCLUDING A FLOOR-DEFINING BOTTOM WALL AND VERTICAL SIDE WALLS LATERALLY SPACED FROM THE CASING AT THEIR LOWER PORTIONS, SAID RECEIVER TOGETHER WITH THE INTERIOR OF THE CASING ABOVE IT DEFINING A PRIMARY COMBUSTION CHAMBER, THE SIDE WALLS OF SAID RECEIVER APPROACHING THE CASING SIDE WALLS AT A MID-HEIGHT REGION THEREOF AND THERE HAVING LATERAL OUTWARD FLANGES HORIZONTALLY SPACING IT FROM THE CASING SIDE WALLS TO FORM VERTICAL AIR FLOW PASSAGES UPWARDLY ALONG THEM TO SAID COMBUSTION CHAMBER, AND A CARBURETTING BURNER HEAD AT THE TOP OF THE CASING AND THERE DEFINING A SECOND COMBUSTION CHAMBER, SAID BURNER HEAD COMPRISING A COVER-LIKE SUPPORTING PLATE FITTING AND REMOVABLY SEATING ON THE CASING TOP AND HAVING A LARGE CENTRAL APERTURE, AN UPSTANDING PERFORATE WALL SURROUNDING AND VERTICALLY OPEN TO SAID APERTURE AND HAVING A HORIZONTAL TOP WALL DEFINING WITH SAID PERFORATE WALL A TOPCLOSED SECOND COMBUSTION CHAMBER, A HORIZONTAL BOTTOM PLATE OF SIMILAR CIRCUMFERENTIAL EXTENT AS AND SPACED BELOW SAID SUPORTING PLATE AND HAVING A VERTICAL MARGINAL WALL CONNECTING IT TO SAID SUPPORTING PLATE TO FORM THEREWITH AN INTERMEDIARY CHAMBER BETWEEN THE PRIMARY COMBUSTION CHAMBER OF THE CASING AND SAID SECOND COMBUSTION CHAMBER, SAID BOTTOM PLATE HAVING A MAIN CENTRAL APERTURE CONCENTRIC WITH BUT OF SMALLER DIAMETER THAN THE CENTRAL APERTURE OF SAID SUPPORTING PLATE AND ALSO HAVING A SERIES OF RELATIVELY SMALL APERTURES DISTRIBUTED ABOUT SAID MAIN CENTRAL APERTURE AND SAID SUPPORTING PLATE ALSO HAVING A CIRCUMFERENTIALLY DISTRIBUTED APERTURE SERIES RADIALLY OUTWARD OF SAID BOTTOM PLATE APERTURES, SAID BURNER HEAD FURTHER COMPRISING A VERTICAL STACK RING SURROUNDING AND ANNULARLY SPACED FROM SAID UPSTANDING PERFORATE WALL OF THE HEAD AND CARRIED ON AND ABOVE SAID SUPPORTING PLATE, SAID STACK RING, SAID PERFORATE-WALLED SECOND COMBUSTION CHAMBER AND SAID INTERMEDIARY CHAMBER AND ALL SAID APERTURES THEREOF TOGETHER BEING CONSTRUCTED AND ARRANGED TO PROVIDE PASSAGES FOR JET FLOW OF EXTERNAL SUPPLEMENTAL AIR LATERALLY AND INWARDLY VIA SAID INTERMEDIARY CHAMBER TO SAID SECOND COMBUSTION CHAMBER SO AS TO CONTACT TRANSVERSELY AND PROGRESSIVELY ALONG THE FLOW DIRECTION IGNITED STREAMS OF COMBUSTION GASES FLOWING UP FROM THE PRIMARY COMBUSTION CHAMBER OF THE CASING AND THEREBY CONTINUING IN SAID SECOND CHAMBER BY HYDROXYLATIVE COMBUSTION THE BURNING OF SUCH GASES. 